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                            <div style="color:gray; word-break: break-all; font-size:12px;">原英文版地址: <a href="https://www.elastic.co/guide/en/elasticsearch/reference/7.7/indices-flush.html" rel="nofollow" target="_blank">https://www.elastic.co/guide/en/elasticsearch/reference/7.7/indices-flush.html</a>, 原文档版权归 www.elastic.co 所有<br/>本地英文版地址: <a href="../en/indices-flush.html" rel="nofollow" target="_blank">../en/indices-flush.html</a></div>
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<strong>重要</strong>: 此版本不会发布额外的bug修复或文档更新。最新信息请参考 <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html" rel="nofollow">当前版本文档</a>。
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<h2 class="title">
<a id="indices-flush"></a>Flush API<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h2>
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<p>Flushes one or more indices.</p>
<div class="pre_wrapper lang-console">
<pre class="programlisting prettyprint lang-console">POST /twitter/_flush</pre>
</div>
<div class="console_widget" data-snippet="snippets/1630.console"></div>
<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="flush-api-request"></a>Request<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h3>
</div></div></div>
<p><code class="literal">POST /&lt;index&gt;/_flush</code></p>
<p><code class="literal">GET /&lt;index&gt;/_flush</code></p>
<p><code class="literal">POST /_flush</code></p>
<p><code class="literal">GET /_flush</code></p>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="flush-api-desc"></a>Description<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h3>
</div></div></div>
<p>Flushing an index is the process of making sure that any data that is currently
only stored in the <a class="xref" href="index-modules-translog.html" title="Translog">transaction log</a> is also
permanently stored in the Lucene index. When restarting, Elasticsearch replays any
unflushed operations from the transaction log into the Lucene index to bring it
back into the state that it was in before the restart. Elasticsearch automatically
triggers flushes as needed, using heuristics that trade off the size of the
unflushed transaction log against the cost of performing each flush.</p>
<p>Once each operation has been flushed it is permanently stored in the Lucene
index. This may mean that there is no need to maintain an additional copy of it
in the transaction log, unless <a class="xref" href="index-modules-translog.html#index-modules-translog-retention" title="Translog retention">it is retained
for some other reason</a>. The transaction log is made up of multiple files,
called <em>generations</em>, and Elasticsearch will delete any generation files once they are no
longer needed, freeing up disk space.</p>
<p>It is also possible to trigger a flush on one or more indices using the flush
API, although it is rare for users to need to call this API directly. If you
call the flush API after indexing some documents then a successful response
indicates that Elasticsearch has flushed all the documents that were indexed before the
flush API was called.</p>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="flush-api-path-params"></a>Path parameters<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h3>
</div></div></div>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
<code class="literal">&lt;index&gt;</code>
</span>
</dt>
<dd>
<p>
(Optional, string) Comma-separated list or wildcard expression of index names
used to limit the request.
</p>
<p>To flush all indices,
omit this parameter
or use a value of <code class="literal">_all</code> or <code class="literal">*</code>.</p>
</dd>
</dl>
</div>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="flush-api-query-params"></a>Query parameters<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h3>
</div></div></div>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
<code class="literal">allow_no_indices</code>
</span>
</dt>
<dd>
<p>
(Optional, boolean) If <code class="literal">true</code>,
the request does <span class="strong strong"><strong>not</strong></span> return an error
if a wildcard expression
or <code class="literal">_all</code> value retrieves only missing or closed indices.
</p>
<p>This parameter also applies to <a class="xref" href="indices-aliases.html" title="Update index alias API">index aliases</a>
that point to a missing or closed index.</p>
<p>Defaults to <code class="literal">true</code>.</p>
</dd>
<dt>
<span class="term">
<code class="literal">expand_wildcards</code>
</span>
</dt>
<dd>
<p>(Optional, string) Controls what kind of indices that wildcard expressions can
expand to. Multiple values are accepted when separated by a comma, as in
<code class="literal">open,hidden</code>. Valid values are:</p>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
<code class="literal">all</code>
</span>
</dt>
<dd>
Expand to open and closed indices, including <a class="xref" href="index-modules.html#index-hidden">hidden indices</a>.
</dd>
<dt>
<span class="term">
<code class="literal">open</code>
</span>
</dt>
<dd>
Expand only to open indices.
</dd>
<dt>
<span class="term">
<code class="literal">closed</code>
</span>
</dt>
<dd>
Expand only to closed indices.
</dd>
<dt>
<span class="term">
<code class="literal">hidden</code>
</span>
</dt>
<dd>
Expansion of wildcards will include <a class="xref" href="index-modules.html#index-hidden">hidden indices</a>.
Must be combined with <code class="literal">open</code>, <code class="literal">closed</code>, or both.
</dd>
<dt>
<span class="term">
<code class="literal">none</code>
</span>
</dt>
<dd>
Wildcard expressions are not accepted.
</dd>
</dl>
</div>
<p>Defaults to <code class="literal">open</code>.</p>
</dd>
<dt>
<span class="term">
<code class="literal">force</code>
</span>
</dt>
<dd>
<p>(Optional, boolean)
If <code class="literal">true</code>,
the request forces a flush
even if there are no changes to commit to the index.
Defaults to <code class="literal">true</code>.</p>
<p>You can use this parameter
to increment the generation number of the transaction log.</p>
<p>This parameter is considered internal.</p>
</dd>
<dt>
<span class="term">
<code class="literal">ignore_unavailable</code>
</span>
</dt>
<dd>
(Optional, boolean) If <code class="literal">true</code>, missing or closed indices are not included in the
response. Defaults to <code class="literal">false</code>.
</dd>
<dt>
<span class="term">
<code class="literal">wait_if_ongoing</code>
</span>
</dt>
<dd>
<p>(Optional, boolean)
If <code class="literal">true</code>,
the flush operation blocks until execution
when another flush operation is running.</p>
<p>If <code class="literal">false</code>,
Elasticsearch returns an error
if you request a flush
when another flush operation is running.</p>
<p>Defaults to <code class="literal">true</code>.</p>
</dd>
</dl>
</div>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="flush-api-example"></a>Examples<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h3>
</div></div></div>
<div class="section">
<div class="titlepage"><div><div>
<h4 class="title">
<a id="flush-api-specific-ex"></a>Flush a specific index<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h4>
</div></div></div>
<div class="pre_wrapper lang-console">
<pre class="programlisting prettyprint lang-console">POST /kimchy/_flush</pre>
</div>
<div class="console_widget" data-snippet="snippets/1631.console"></div>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h4 class="title">
<a id="flush-multi-index"></a>Flush several indices<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h4>
</div></div></div>
<div class="pre_wrapper lang-console">
<pre class="programlisting prettyprint lang-console">POST /kimchy,elasticsearch/_flush</pre>
</div>
<div class="console_widget" data-snippet="snippets/1632.console"></div>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h4 class="title">
<a id="flush-api-all-ex"></a>Flush all indices<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/indices/flush.asciidoc">edit</a>
</h4>
</div></div></div>
<div class="pre_wrapper lang-console">
<pre class="programlisting prettyprint lang-console">POST /_flush</pre>
</div>
<div class="console_widget" data-snippet="snippets/1633.console"></div>
</div>

</div>

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